apparatus for handling sheets



March 1954 w. R. MULQUIN ETAL APPARATUS FOR HANDLING SHEETS 5 Sheets-Sheet 1 Filed June 5, 1959 March 17, 1964 w. R. MULQUIN ETAL 3,

APPARATUS FOR HANDLING SHEETS INVENTORS ATTORNEY 7 Ludwig Moll/1:9

5 Sheets-Sheet 2 MY/iam R- Filed June 5, 1959 March 17, 1964 Filed June 5, 1959 w. R. MULQUIN ETAL 3,125,229

APPARATUS FOR HANDLING SHEETS 5 Sheets-Sheet 3 ATTORNEY Mar-ch 17, 1964 w. R. MULQUIN IITAL 3,125,229

APPARATUS FOR HANDLING SHEETS 5 Sheets-Sheet 4 Filed June 5, 1959 INVENTORS l'i il/iam R. Mu/qw'n Lao 101:9 Mo/wiq Jr- 8 .1 BY ATTORNEY March 1964 w. R. MULQUIN ETAL 3, 25,

' APPARATUS FOR HANDLING SHEETS Filed June 5, 1959 5 Sheets-Sheet 5 INVENTORS l i l'l/iam R. Mi /7 um Jr:

United States Patent 3,125,229 APPARATUS FOR HANDLHIG SHEETS William R. Mulquin, Baltimore, Md., and Ludwig Molvig, In, Bethlehem, Pa, assignors to Bethlehem Steel Company, a corporation of Pennsylvania Filed June 5, W59, Ser. No. 818,457 6 Claims. (Cl. 2ll48.5)

This invention relates to apparatus (for handling sheet material such as tin plate, etc. More particularly this invention relates to improved apparatus for handling sheet material such as tin plate, etc. during inspection.

It is the practice to inspect tin plate and similar sheet material visually. Ordinarily both sides of the sheet are inspected consecutively. This procedure entails visually inspecting one side of the sheet and then turning it over and visually inspecting the other side of the sheet. Until recently the sheet has been manually flipped or turned over by the inspector.

According to present custom the inspector stands at the inspection table upon which a pile of sheets is placed in a stack. He observes the condition of the top of the first sheet in the pile and then grasps the sheet and turns it face down on to the table next to the pile and observes the condition of the other side of the sheet. The top surface of the next sheet in the pile or stack is next inspected and then this second sheet in turn is grasped and flipped down on top of the first sheet with the previous bottom surface of the second sheet facing up in position for inspection. This alternate visual inspection of one side of the sheet and the subsequent flipping over of the sheet and the inspection of the other side is continued until all the sheets have been visually inspected on both sides and all of the perfect sheets have been trans ferred from the first pile to the second pile. When the inspector notes a sheet with an imperfection on either side he manuaily discards this sheet into another pile for imperfect sheets. Such manual handling of the sheets is tedious, time consuming and requires considerable labor.

It is an object of the present invention therefore to provide improved handling apparatus whereby the inspection of sheet material is facilitated.

It is a further object of the present invention to provide apparatus whereby sheet material such as tin plate may easily, quickly, and with a minimum of manual handling, be visually inspected on both sides.

To this end we have provided an apparatus which cornprises means to receive a pile of sheets to be inspected from a conveyor in a flat condition and upends said pile of sheets on one edge, means to subject the said sheets while on one edge to the influence of a magnetic field which induces like magnetic polarities in contiguous edges of the sheets whereby the sheets tend to repel each other and separate along the edge next to the source of the magnetic field; a rotating spiral turndoWn member which engages the separated edge of each sheet and smoothly and efiiciently turns the sheets down one by one; and a conveyor which receives the turned-down sheets and conveys the said sheets away, preferably to a classifier which is operable to direct them to appropriate piles. The inspector, by standing adjacent to the point where the sheets are turned-down onto the conveyor, is enabled to inspect the outer side of each outermost sheet as it stands on edge in the upended pile and to inspect the other side of each sheet after it has been turned-down individually onto the conveyor by the action of the spiral tnrndown member, and if the sheet has no visible defects therein it will be delivered automatically by the classifier to the pile reserved for perfect sheets. However, if the sheet has a visible detect, the inspector has at his disposal suitable switches or controls which allow him to operate the classifier to direct the sheets individually to any ice of several reject piles according to his judgment as to the relative severity of the defect which he has observed on the surface of the sheet.

Other and further objects of the invention will be apparent to those skilled in the art [from the following detailed description of the annexed sheets of drawings in which, by way of a preferred example only, one embodiment of the invention is illustrated, and in which:

FIGURE 1 is a perspective view of the entire sheet inspection and handling device including feeding and discharging conveyor and classifier systems.

FIGURE 2 is an elevation of the sheet turning device showing its positional relation to the upender of the inspection device.

FIGURE 3 shows upender body rotated into receiving position.

FIGURE 4 is a view of the sheet turning device along 4--4- of FIGURE 2.

FIGURE 5a is a front elevation of the supporting stand and track assembly for the sheet turning device, and the rotary upender.

'FIGURE 5b is a side elevation of the supporting stand and track assembly, and the rotary upender.

FIGURE 6a is a side detail of the track assembly supported by adjusting stand of FIGURE 5a.

FIGURE 6b is a top detail of the track assembly of FIGURE 6a.

FIGURE 7 is an enlarged side elevation of the spiral sheet turndown assembly.

FIGURE 8 is an end elevation of the spiral sheet turndown, device assembly of FIGURE 7.

FIGURE 9 is a bottom view of the spiral sheet turndown assembly of FIGURE 7.

FIGURE 10 is an isometric assembly view of the polarity inducing magnet assembly. I The present embodiment of the instant sheet inspection and handling apparatus as shown in the drawings comprises four principal units, designated 11, 12, '13 and 14. 11 is a conveyor and classifier unit on which one side of each sheet is visually inspected by the inspector and which then conveys the sheet to one of three piles according to the condition of the surface of the sheet as determined by the inspector. 14 is a roller table unit for a pile of sheet. '12 is a rotary unender unit intermediate the unit 14 and the unit 11 which is adapted to receive piles of sheets in a horizontal position from the unit 14 and upend the pile as a unit to an almost vertical position adjacent the feed end of the conveyor of the unit 11, with the bottom edge of each sheet supported on the upender, so that the inspector can observe the top or outermost surface of each sheet in the said pile. 13 is a unit comprising a sheet turning device together with adjustable supporting means therefor, the sheet turning device acting to engage each sheet individually as it rests on edge on the upender 12 and to turn the said sheet down onto the conveyor of the unit 11 after its outermost surface has been visually inspected by the inspector.

The unit 14 consists of a main frame 21 Within which are journaled for rotation a series of rollers 23 which may be powered for rotation in any conventional manner, not shown; said rollers 23- being adapted to convey' a pile of sheets 24 to be inspected across the surface of said rolls to the rotary upender unit 12. The sheets are shown supported on a pallet 25 such as ordinarily used in conjunction with a fork lift truck.

The upender unit 12 consists of a base 26 on which are journaled power operated rollers 27 which rotatably support a movable upender body 28. The upender body 28 consists of a rotatable arcuate base support 29 with a arcuate outside surface '30 adapted to engage and to be operated by the power operated rollers 27. The inside of the upender body 28 consists of two work sup porting surfaces 31 and 32 respectively arranged perpendicularly or at right angles to each other and supported by the rotatable arcuate base support 29. One of these surfaces 3 1 is composed of rollers 33 rcvolvably journaled into the rotatable arcuate base support 29 similar to the rollers 23 on the roller table conveyor unit 14 and so arranged that when the rotary upender body 28 is rotated into the receiving position with the surface 31 horizontally disposed, as shown in FIGURE 3 of the drawings, the rollers 33 of the rotary upender 12 and the rollers 23 of the roller table conveyor 14 are disposed in substantially the same plane or surface so that a pile of sheets such as shown at 24- can be conveyed along the rollers 23 directly onto the rollers 33 until the sides of the sheets rest against the surface 32 of the hat plate 34, which is disposed vertically when the rotary upender body 28 is in the receiving position. When the body 28 of the rotary upender unit 12 is rotated to its discharging position, as shown in FIGURES 1 and 2, the fiat plate 34 constituting the surface 32 is disposed at an angle of about 10 degrees from the horizontal and the surface 31 as constituted by the rollers 33 being perpendicular to the plane of the surface 32 is consequently disposed at an angle of approximately 10 degrees from the vertical. In this position a pile of sheets designated 35 will rest on edge on the plate 34 with a flat surface back against the rollers 33, as shown in FIGURE 1, in position to be operated upon by the sheet turning device of the unit 13.

Located adjacent to the upender 12 is the unit 13 comprising the sheet turning device and the adjustable supporting means therefor. The sheet turning device is designated as a whole in the figures as 613- and the adjustable supporting stand which supports it is designated as a whole at 64.

The adjustable supporting stand 64 comprises, as shown in :FIGURES A and SE, a base 65 supporting an upright column 67. To one side of the column 67 and rotatably journaled in brackets 68 and 6 9, which brackets are secured to the column 67, is a long adjusting screw 70. At the lower end of the screw 70 and secured thereto is a sprocket wheel 71. Supported on a bracket 72 which is in turn supported from a central part of the bracket 69 is a motor 73. On the shaft of the motor '73 is a second sprocket wheel 74. A sprocket chain 75 conmeets the two sprocket wheels 71 and 74 and enables the motor 73 to turn the screw 70. Threaded onto the screw 70 are two brackets 76 and 77 to which is fixed a support frame 78, having a hollow horizontally disposed member 79 constituting a support for the sheet turning device 63. Attached to both sides of the two brackets 76 and 77 and extending around the column 67 in sliding relation therewith is a yoke member 30. When the screw member 70 is turned by the motor 73 in either direction the yoke member 80 bears against the column 67 and prevents the two brackets '76 and 77 from rotating with the member 70. Since the brackets 76 and 77 are held from rotating, the rotation of the member 70 being threaded through the said brackets 76 and 77 causes the brackets to be carried up or down the member 71} depending upon the direction of rotation of the said member. A set screw 811A extends through the yoke member 811 into contact with the column 6 7 and holds the yoke 8d and the support structures attached thereto in any given adjusted position upon the column 67.

The sheet turning device 63 as shown in FIGURES 2, 4, 7, 8 and 9 comprises a track assembly composed of a flat plate 85 having mounted thereon at the opposite sides thereof, track rails 86 and 87, said plate having a pair of supporting brackets 82 and 83 extending upwardly therefrom. A circular elongated member 81 passes through the upper ends of the brackets 82 and 83 and constitutes a support for adjustably connecting the sheet turning device 63 to the support frame 78, the member 81 being mounted in the hollow member 79 of said supporting frame 78.

The sheet turning device 63 also comprises a carriage designated as 94, upon which is mounted the spiral turndown member 111 and the magnet assembly 131). The carriage 94 comprises a plate member 95 and two upwardly extending side plates 96 and 97 connected thereto. Mounted in each of said side plates adjacent the upper edge thereof at each end is a stub axle 98 on each of which are journaled grooved wheels 99" which are mounted on the track rails 86 and 87 with the carriage 94 suspended beneath said tracks. At one end of and midway between the tracks 86 and 87 is supported a sheave 88. Vertically supported from one of the brackets 82 or 8 3 is a post 89 having at the top thereof a crosspiece 90. On the crosspiece 9d and the post 89 are rotatably supported sheaves 91, 92, and 93 for a purpose which will hereafter be explained.

On one side of the carriage 94 and depending from the under side of and attached to the plate 95 are two brackets 1% and 1111. In the lower ends of these brackets and extending between them is journaled a shaft 102 having fixed on one end thereof by a nut 103 a pulley 1M, and secured to and around the shaft 102 between the two brackets 1M and 101 is a rotatable spiral turndown member 111 best shown in FIGURES 7, 8 and 9. At the other end and to one side of the carriage 94 supported on 21 depending L-shaped bracket 105 is an electric motor 106 having a pulley 107 secured to the end of its armature shaft by a nut 108. The pulleys 1114 and 107 are connected by a belt 199 so that the motor may drive the shaft 102.

The rotatable spiral turndown member 111 may take various forms but in the present embodiment of our invention as shown in the drawings comprises a flat blade 112 which we term the cutting blade or cut out blade 112 and a narrow spiral blade which we term the spiral turndown blade or member 113. The member 113 is secured to the back of the cut out blade 112 and the shaft 102 at 114- and is at its other extremity also secured to the shaft 162 at 115 and spirals around the shaft 1112 between points 114 and 115 as best seen in FIGURES 7 and 9. The cut out blade 112 as best shown in FIGURE 8 consists of a flat arcu-ate blade with an extent slightly more than that of a half circle. It will be understood that when the motor 106 rotates the shaft 102 the spiral turndown member 111 being fixed to the shaft 102 will be rotated therewith. This rotation should be in a clockwise direction as viewed from point 114 along shaft 132.

At the opposite end of the carriage 94 from the shaft 102 and opposite bracket 195 is a bracket 121 dependently secured to the carriage 94-. The dependent bracket 121 has two downwardly turned extensions or arms 122 and 123. These two arms 122 and 123 cooperate to support the long bolts 12dand 125 passed through and between slots 126 in the arms 1 22 and 123 and frictionally secured in any desired position in the slots 126 by tightening nuts 127 and 128 on threaded ends of the bolts 124 and 125. The long bolts 124 and 125 in turn are adapted to pass through and support a magnetic-polarity inducing device assembly 131 which in the present embodiment, as best shown in FIGURE 10, comprises two permanent horseshoe magnets with adjacent like poles shown in outline in FIGURE 10' as 131 and 132 and enclosed within a brass sheet or non-magnetic material holder consisting of a supporting piece 133 having a flat base 138 and two upwardly extending arms 1.34 and 135 adapted to extend between the arms 122 and 123 of the bracket 121 to be engaged and held by the long bolts 12dand 125 passing through the holes 136 in the arms 134 and 135, and a tie down plate 137 of sheet brass, etc., which passes over the magnets 131 and 132 and is secured to the base portion 138 of the support piece 133 to securely hold the magnets 13 1 and 132 in place on the base portion 138 of the support piece 133.

The four grooved wheels 99 of the carriage 94 are designed to run freely upon the rails or tracks 86 and 87.

As previously mentioned the rotary upender body 28 when in the operating position shown in FIGURE 2 is slightly rotated from the horizontal so that the surface 32 constituted by the flat plate 34 is tipped from the horizontal by about degrees. The surface 31 against which the pack of sheets. 35 rests is consequently also tipped away from the vertical by about 10 degrees so that the sheets will ordinarily not topple away from the said surface 31 of their own accord. The top surface 141) of the pack of sheets 35 as constituted by the top edges of all the sheets taken together consequently is also tipped from the horizontal to the same degree as the surface 32. It is desired to have the carriage 94 travel along the tracks 86 and 87. above the pack of sheets 35 at a constant distance from the top of said sheets. To accomplish this the support 81 is adjusted within the member 75 of the support 78 of the adjustable stand 64 so that the tracks 86 and 87 are inclined to the horizontal by the same degree, approximately 10 degrees, as the surface 32. A set screw 84 is provided to retain the support 81 in the desired position. At this angle of inclination of the tracks 86 and 87 the carriage 94 will tend to run down the said tracks under the influence of gravity. However, to prevent the carriage 94 from freely running down the tracks 56 and 87 it is counterbalanced by a weight 141 as best seen in FIGURE 2. A light line or wire 142 is secured to the upper end of the carriage 94 as at 143 and passed around the sheaves 38, 91, 92 and 93 in that order and has the weight 141 secured to its end, the weight 141 being selected to be sufficient to counterbalance the weight of the carriage 94 on the tracks 86 and 87. In the present embodiment of our invention the carriage 94 is manually moved along the tracks 86 and 87 by means of the handle 144 to its correct operative position above the pack of sheets 35. Because of the counterbalancing of the weight 141 against the weight of the carriage 94 the said carriage containing the magnet assembly 130 and the rotatable spiral turndown member 111 will maintain any given position in which it is placed along tracks 86 and 87 until again moved by the inspector.

The conveyor and classifier unit 11 consists of a base or frame 36 in which are suitably journaled shafts 37, 38 and 39. On the shafts 37, 38 and 39 are rollers collectively designated as 40. The rollers 40 have running over and around them, and constitute the bearing means and support for, two conveyor belts 41 and 42. One or more of the shafts 3'7, 38, and 39, or the rollers 46) are connected to a power means, not shown, to drive the rollers 49 and consequently the conveyor belts 41 and 42 which run over and around them. As shown in FIGURE 1 two small sections of the fiat plate 34 which constitutes surface 32 of the rotary upender body 28 are cut out at 43 to allow room for the rollers held on the shaft 37 and the ends of the conveyor belts 41 and 42 passed therearound to be partly surrounded by the flat surface 32.

Referring to FIG. 1, the frame pieces 44, indicated by solid lines, and 45, indicated by dotted lines, have roller support 46 fixed in frame piece 45, and roller support 46a fixed within frame piece 44 and indicated in FIG- URE 1 by dotted lines, in which roller supports two sets of rollers, a top set 47a and a bottom set 47b are rotatably journaled. These roller sets 47a and 47b may be power driven or they may be set in an inclined plane, one set, for instance, such as 47a may be inclined towards the near side as viewed in FIGURE 1 and the other set 47b may be inclined towards the far side as viewed in FIGURE 1. If a sheet is placed on either inclined set of rollers 47a or 47b it will be activated by gravity and will roll therealong and slide off the end of the said inclined set of rollers to one side or the other of the unit 11. In the present embodiment of the instant device a sheet placed on the set of rolls 47a will either, by virtue of power applied to the rolls or by virtue of the action of gravity acting on the sheet along an inclined plane constituted by the set of rollers 47a, be propelled off the near side, as viewed in FIGURE 1, of the unit 11 and will fall into a receptacle, generally designated as a piler 54, which comprises a short roller conveyor 48 and two shields 49 and 50 which act to keep the sheets falling onto the roller conveyor 48 in alignment so as to form a pile, and a swinging plate which constitutes a damping shield 52 attached to a shaft 51 which is journaled into the two shields 49 and 50. Any sheets falling between the shields 4% and 50 from or off the set of rolls 47a will tend to strike the swinging shield 52 which will be swung or deflected by the blow. The horizontal component of the energy of movement of the falling plate is thereby partly transferred to the swinging shield 52 which then slowly dissipates the said energy in friction against the air and at its shaft hearing surfaces by virtue of its swinging movement. On the far side as viewed in FIGURE 1 of the unit 11 where sheets leave the other set of rolls 47b is located a receptacle for the sheets generally designated as piler 53, which comprises a duplication of the short roller conveyor 48, the two shields 49 and 50, shaft 51 and swinging shield 52. At the end of the two conveyor belts 41 and 42 is another piler 55 identical with piler 53 and 54. Journaled on shafts into frame unit 45 are the two rollers 56 and 57 which may also be power driven or merely freely rotatable. The top surfaces of the two rollers 56 and 57 are respectively on a level with or slightly higher than the two sets of rollers 47a and 47b so that a sheet passing over one of them will be propelled onto one of the respective sets of rollers 47a and 47b. Mounted on the unit 11 in advance of the rolls 56 and 57 is a solenoid operated gate 58. The gate 58 as shown in FIGURE 1 is located between the conveyor belts 41 and 42 and has one end thereof pivotally mounted at 59. The gate 58 may be operated vertically about the pivot 59 to different positions by any suitable mechanism such as a solenoid operated device. The gate 58 has three positions. The normal position of the gate is as show in FIGURE 1. In this position the gate is positioned just below the tops of the two conveyor belts 41 and 42 so that it will not contact any sheets being conveyed on the conveyor belts 41 and 42. A second position of the gate 58 is with the gate 58 tipped so that its top edge 60 is on a level with the top edge of the roller 57. When the gate 58 is in this second position any sheet moving along the conveyor belts 41 and 42 will be deflected upward by the gate 58 over the roller 57 and onto the set of rolls 47/11. A third position of the gate 58 places its top edge 60 on a level with the roll 56 so that a sheet being carried along the conveyor belts 41 and 42 will be deflected upwardly and over the roller 56 onto the set of inclined rollers 47a.

The method of operation of our handling device will now be explained. With the upender unit 12, in the position shown in FIG. 1 or 2 and a pile of sheets to be inspected such as 24 shown in FIGURE 1 on a pallet 25 on the roller table conveyor unit 14 the operator or inspector operates some suitable control means to operate a motor within the base 26 of the rotary upender unit 12 which motor is operatively connected to the rollers 27 and through their agency rotates the rotary upender from the discharging position shown in FIGURE 1 into the charging position, as shown in FIG. 3, in which position the rollers 33 on the rotary upender form a continuous surface with the rollers 23 on the roller conveyor table 14 and the stack or pile of sheets 24 is conveyed by suitable means onto the rotary upender until the edges of the sheets in the pile butt against the plate 34.

i As shown in FIGURES 5a and 5b a cable 66a links the rotary upender body 28 and the lower bracket 69 supported on the column 67 of the adjustable supporting stand 64 which carries the sheet turning mechanisms 63 in a manner such that when the rotary upender body 28 rotates to loading position as shown in FIGURE a the tension on cable 66:: is relaxed and spring 66b, also secured to bracket 69, will be able to rotate column 67 90 on its base 65 until stop lugs, not shown, in said base 65 stop the rotation. When the rotary upender body 28 returns to discharging position, as shown in FIGURE 5b, tension will be re-exerted on cable 66a and column 67 will thereby be rotated back 90 degrees on its base 65 against the tension of spring 66b. For clarity in FIG- URES 5a and 5b, the rotary upender 28 and the adjustable supporting stand 64 are shown farther away from each other than they would actually be. The rotation of the column 67 acts to swing the sheet turning device 63 and other associated structures supported by the adjustable supporting stand 64 clear of the rotary upender body 28 so that the said sheet turning device 63 will not interfere with the movement of the rotary upender.

After the pack of sheets 24 is placed on it the rotary upender is rotated back to the discharge position shown in FIGURE 1. As the rotary upender rotates back to discharge position after loading the cable linkage 66a be tween it and the adjustable supporting stand 64 will act to cause the column 67 to again rotate in the base 65 and swing the sheet turning device 63 and associated structures back 90 so that they are returned to their operative position over the rotary upender and adjacent to the top edges of the sheets in the pack, now designated in upended position as 35, as the sheets rest on edge upon the plate 34.

If the sheet turning device 63 is not in the proper po sition above the top edges of the sheets in the pack 35 the inspector will adjust the device 63 by operating the motor 73 of the adjustable supporting stand 64 in the proper direction to turn the screw 70 in the appropriate direction to move the support frame 78 up or down as may be required to position the sheet turning device 63 at the proper distance above the pack for operation.

If a series of packs of sheets of the same dimensions are inspected consecutively the adjustment of the sheet turning device 63 above the top edges of the sheets will ordinarily be necessary but once.

The motor 106 which rotates the spiral turndown member 111 is next activated and the carriage 94 is manually or otherwise moved down the tracks 86 and 87 until the outside of the cut out blade 112 contacts the outer side of the first sheet in the pack. At this point, as may be best seen in FIGURE 2, the magnetic polarity inducing device assembly 130 will be partly positioned over a portion of the pack of sheets 35. The poles of the magnets will induce like magnetic polarities in the portions of the edges of the sheets adjacent to the poles and since like polarities tend to repel each other the adjacent edges of the magnetizable sheets in the pack 35 near the magnet poles will tend to separate from each other. The outer sheet will separate the greatest relative distance from the next nearest sheet as the other sheets will be held back in varying degrees by the weight upon them of the other overlying sheets in the pack as they lie tipped back slightly (approximately 10 degrees from the vertical) against the surface 31 as constituted by the rollers 33. Since the polarity inducing means is adjacent each sheet over only a small portion of the top edge of each sheet, the major portion of the rest of each sheet is substantially unaffected as regards induced polarity therein and acts merely as a dead weight. Thus it has been found that the top edge of the outermost sheet next to the polarity inducing means separates the greatest distance from the next lower sheet. The next sheet because it has almost twice as much weight holding it down, i.e., the major portion of the weight of the first sheet plus its own weight will tend to separate only approximately half as far from the next underlying sheet as the separation of the first sheet from the second. Roughly the same general relationship will hold between the separation of the second sheet and the third sheet, the

third and the fourth, etc. When the outer sheet is com pletely removed from the pack the next lower or second sheet will tend to spring out to the same point or distance from the next lower sheet after that, or the third sheet, as the removed sheet originally was from the second. Each sheet therefore will separate from the pack a certain distance until the force of the magnetic polarity forcing the sheet away from the pack is in equilibrium with the force of gravity on the sheet itself and any overlying sheets urging them back toward the pack.

The cut out blade 112 of the rotating turndown spiral 111, as it is moved against the outer sheet of the pack by movement of the carriage 94 down the tracks 86 and 87, presses the outer sheet toward the pack in opposition to the outward force of the induced like polarities in the edges of the sheets. However, when the arcuate cut out blade 112 has rotated to an upward position as shown in FIGURES 7 and 8 it no longer contacts the sheet and the sheet under the force of the induced polarity in its edge springs away from the pack. The edge 112A of the rotating cut out blade 112 then descends behind the sheet isolating it from the other sheets and the end of the narrow spiral blade 113 contacting the cut out blade 112 at point 114 enters behind the sheet with the cut out blade 112, in contact with the edge of the sheet and the continued rotation of the spiral blade forces the sheet progressively along the spiral, progressively pivoting the sheet about its bottom edge and moving the top edge of the sheet outwardly from the pack until the sheet becomes overbalanced and topples by its own Weight onto the conveyor belts 41 and 42. As the spiral blade 113 forces the sheet away from the pack 35 the weight of the said sheet is progressively removed from the next underlying sheet in the pack 35 which then springs outwardly from the pack 35. However, by the time the weight of the first sheet is completely removed from the pack the cut out blade 112 is in position to contact the outside edge of the second sheet and restrain it from springing outwardly very far from the pack until the edge 112B of the rotating cut out blade 112 passes above the upper edge of the sheet when the said sheet can spring outwardly to its full extent. After the edge 11213 has rotated past the sheet edge allowing the second sheet to spring out, the cycle repeats itself as the edge 112A of the blade 112 descends and cuts out the second sheet, and the spiral blade 113 contacts and forces the sheet away from the pack until it topples over onto the conveyor belts 41 and 42. The third sheet in the pack is then ready to be separated and so on. It is obvious that the rate at which the sheets are cut out and toppled onto the conveyor belts will depend upon how fast the spiral turndown member 111 is rotated by the motor 106. This speed may be adjusted to that most eflicient for the work of the average inspector or may be adjustable by the inspector by means of a rheostat in the circuit with the current supply to electric motor 106 and under the control of the inspector so he may adjust it to the speed he feels is most suitable.

In order to keep the turndown device in operative position, as sheets are removed from the pack 35, it is necessary that the carriage containing this device he moved along the track towards the pack. Various forms of mechanical contrivances may be used for moving the carriage 94 down the tracks such as screw feeds or the like or, as we have found satisfactory, this operation may be eifected manually by the inspector as necessary.

The inspector observes the outer surface of each sheet for defects where it lies slightly inclined as the outermost or topmost sheet in the pack or pile 35. After each sheet is pivoted down onto the conveyor belts 41 and 42 by the action of the spiral turndown member 111 its other surface will be upward and the inspector then observes this surface for any defects.

The conveyor belts 41 and 42 are continuously running at all times while the inspection device is in operation so that as soon as a sheet is pivoted down onto the belts 9 by the action of the spiral turndown means 111 it is immediately carried away by these belts.

If the inspector observes any defect on either surface of the sheet and he wishes to segregate that sheet from the acceptable sheets he will operate a suitable control which will activate the gate 58 away from its lowermost or unactivated position to one of the two active positions so that the sheet will be directed up and over the rollers 56 or 57 and onto the set of rollers 4711 which carry it to and drop it onto piler 54 or onto the set of rollers 47b which will carry it and drop it onto piler 53. The inspector may, for instance, direct scrap sheets to piler 53 and salvageable sheets to piler 54. When the gate 58 is in its lowermost or unactivated position the sheet will automatically pass completely along the conveyor belts 41 and 42 to their end where it will be dumped off onto the piler 55 which will ordinarily be the collecting point for acceptable sheets.

Briefly summing up therefore we have provided a sheet handling apparatus comprising an upender which receives a pile of sheets in a flat condition and upends them on edge; a magnetic polarity inducing device which forces said sheets While on edge on the upender to separate slightly by inducing like polarities in their top edges and a motor driven rotating spiral which inserts its leading edge in the separation between the sheets created by the magnet so that the upper edge of each single sheet is forced along the inclined plane of the spiral, said upper edge thereby being forced outwardly from the pile a sufficient distance so that the sheet is tilted over and falls onto a belt conveyor. An operator standing beside the machine inspects each side of each sheet, one side while the sheet is upright and the other side after it falls onto the belt conveyor, and can by energizing a solenoid operated gate divert sheets from the conveyor belt to various appropriate piles.

By means of the present invention then it is obvious that we have devised a novel and effective sheet handling apparatus which is useful for the handling of sheets and which is particularly adaptable for use in connection with the inspection of sheet material.

Although we have thus described our invention in considerable detail, we do not wish to be limited narrowly to the exact and specific particulars disclosed, but we may also use such substitutes, modifications or equivalents as are included within the scope and spirit of the invention or pointed out in the appended claims.

We claim:

1. Apparatus for selectively removing individual sheets from a pack of sheets stacked on edge, comprising (a) a support for said pack of sheets,

(b) means adjacent the upper end of said pack for separating the upper edge of the foremost sheet from said pack,

() rotatable blade means, independent of said first mentioned means, adjacent the upper end of said pack for successively engaging the individual sheets of said pack, said rotatable blade means including a helical portion for engaging the rear face of the foremost sheet of said pack of sheets after it has been separated from said pack by said first mentioned means to force said face away from the pack and cause said sheet to pivot about its lower edge whereby said sheet is removed from said pack and a second portion adjacent the leading end of said helical portion for engaging the front face of the second sheet of said pack to restrain forward movement of said second sheet while said first sheet is being acted on by said helical portion and pivoted down, and

(d) means for rotating said rotatable blade means.

2. An apparatus for successively removing individual sheets from a pack of sheets disposed on edge comprising (a) a support for said pack of sheets,

(b) means adjacent the upper end of said pack for 10 separating the upper edge of the foremost sheet from said pack,

(0) a rotatable helical blade adjacent the upper end of said pack for engaging the rear face of said foremost sheet to force said face away from the pack and cause said sheet to pivot on its lower edge whereby said sheet is removed from said pack,

(d) a rotatable planar blade adjacent the leading end of said helical blade, for engaging the front face of the second sheet of said pack to restrain forward movement of said second sheet while said foremost sheet is being acted on by said helical blade, said planar blade having a cut back edge to permit the passage of the second sheet therepast after the first sheet has been removed from said pack, and

(e) means for rotating said blades.

3. An apparatus for successively removing individual sheets from a pack of sheets disposed on edge comprising (a) a support for said pack of sheets,

(b) means adjacent the upper end of said pack for separating the upper edge of the foremost sheet from said pack,

(0) a rotatable helical blade adjacent the upper end of said pack for engaging the rear face of said foremost sheet to force said face away from the pack and cause said sheet to pivot on its lower edge whereby said sheet is removed from said pack,

(at) a rotatable planar blade adjacent the leading end of said helical blade, for engaging the front face of the second sheet of said pack to restrain forward movement of said second sheet While said foremost sheet is being acted on by said helical blade, said planar blade having a cut back edge to permit the passage of the second sheet therepast after the first sheet has been removed from said pack,

(e) means for rotating said blades, and

(f) a conveyor adjacent said pack of sheets to receive and carry away sheets which have been removed from said pack by said helical blade.

4. An apparatus for successively removing individual sheets from a pack of sheets disposed on edge comprising (a) a support for said pack of sheets,

(b) means adjacent the upper end of said pack for separating the upper edge of the foremost sheet from said pack,

(0) a rotatable helical blade adjacent the upper end of said pack for engaging the rear face of said foremost sheet to force said face away from the pack and cause said sheet to pivot on its lower edge whereby said sheet is removed from said pack,

((1) a rotatable planar blade adjacent the leading end of said helical blade, for engaging the front face of the second sheet of said pack to restrain 'forward movement of said second sheet While said foremost sheet is being acted on by said helical blade, said planar blade having a cut back edge to permit the passage of the second sheet therepast after the first sheet has been removed from said pack,

(e) means for rotating said blades,

(f) a carriage to movably support said separating means and said blades in operative position adjacent the upper end of said pack of sheets, and

(g) a conveyor adjacent said pack of sheets to receive and carry away sheets whch have been separated from said pack by said helical blade.

5. An apparatus for successively removing individual sheets from a pack of ferromagnetic sheets disposed on edge, comprising (a) a support for said pack of sheets,

(b) a magnet adjacent the upper end of said pack for separating the upper edge of the foremost sheet from said pack,

(0) a rotatable helical blade adjacent the upper end of said pack for engaging the rear face of said fore 1 1 most sheet to force said face away from the pack and cause said sheet to pivot on its lower edge whereby said sheet is removed from said pack,

(d) a rotatable planar blade adjacent the leading end of said helical blade, for engaging the front face of the second sheet of said pack to restrain forward movement of said second sheet While said foremost sheet is being acted on by said helical blade, said planar blade having a cut back edge to permit the passage of the second sheet therepast after the first sheet has been removed from said pack, and

(e) means for rotating said blade.

6. An apparatus for successively removing individual sheets from a pack of ferromagnetic sheets disposed on edge, comprising (a) a support [for said pack of sheets,

(12) a magnet adjacent the upper end of said pack for separating the upper edge of the toremost sheet ttrom said pack,

(a) a rotatable helicarl blade adjacent the upper end of said pack for engaging the rear face of said foremost sheet to force said face away from the pack and cause said sheet to pivot on its lower edge whereby said sheet is removed from said pack,

(d) a rotatable planar blade adjacent the leading end of said helical blade, for engaging the front face of the second sheet of said pack to restrain forward movement of said second sheet While said foremost sheet is being acted on by said helical blade, said planar blade having a cut back edge to permit the passage of the second sheet 'therepast after the first sheet has been removed tfI'OHl said pack,

(e) means for rotating said blades,

(f) a carriage to movably support said separating means and said blades in operative position adjacent the upper edge of said pack of sheets, and

(g) a conveyor adjacent said; pack of sheets to receive and carry away sheets which have been separated from said pack by said helical blade.

References Cited in the file of this patent UNITED STATES PATENTS 440,401 Ethridge Nov. 11, 1890 1,716,602 Ross June 11, 1929 1,847,812. Bu nton Mar. 1, 1932 1,971,574 Moon Aug. 28, 1934 2,141,394 I-versen Dec. 27, 1938 2,541,985 Chatterton ,Feb. 20, 1961 2,596,386 Egge May 13, 1952 2,650,824 Fowler Sept. 1, 1953 2,831,407 Pittman Apr. 22, 1958 

1. APPARATUS FOR SELECTIVELY REMOVING INDIVIDUAL SHEETS FROM A PACK OF SHEETS STACKED ON EDGE, COMPRISING (A) A SUPPORT FOR SAID PACK OF SHEETS, (B) MEANS ADJACENT THE UPPER END OF SAID PACK FOR SEPARATING THE UPPER EDGE OF THE FOREMOST SHEET FROM SAID PACK, (C) ROTATABLE BLADE MEANS, INDEPENDENT OF SAID FIRST MENTIONED MEANS, ADJACENT THE UPPER END OF SAID PACK FOR SUCCESSIVELY ENGAGING THE INDIVIDUAL SHEETS OF SAID PACK, SAID ROTATABLE BLADE MEANS INCLUDING A HELICAL PORTION FOR ENGAGING THE REAR FACE OF THE FOREMOST SHEET OF SAID PACK OF SHEETS AFTER IT HAS BEEN SEPARATED FROM SAID PACK BY SAID FIRST MENTIONED MEANS TO FORCE SAID FACE AWAY FROM THE PACK AND CAUSE SAID SHEET TO PIVOT ABOUT ITS LOWER EDGE WHEREBY SAID SHEET IS REMOVED FROM SAID PACK AND A SECOND PORTION ADJACENT THE LEADING END OF SAID HELICAL PORTION FOR ENGAGING THE FRONT FACE OF THE SECOND SHEET OF SAID PACK TO RESTRAIN FORWARD MOVEMENT OF SAID SECOND SHEET WHILE SAID FIRST SHEET IS BEING ACTED ON BY SAID HELICAL PORTION AND PIVOTED DOWN, AND (D) MEANS FOR ROTATING SAID ROTATABLE BLADE MEANS. 